An unusual Roman bronze artifact, recently purchased at a flea market in Zadar, Croatia, was the first in a series of archaeological findings that lead to the discovery of a Roman “film” projector from the first century AD.

3-D computer rendering of the Roman projector component, with animation slide and facing mirror.
The bronze artifact featured in “Ancient Cinema” is unique among Roman metal work in its form; cast in one piece, it tapers from a width of 1 cm at its tip to 8.5 cm at the base, and is 33cm long. A 7-cm-high “side slot,” which juts out beyond the base at a 15-degree angle, adds an additional 3 cm to the length. Facing the “side slot,” is a 16-cm-high support for a mirror. (Romans made glass mirrors by inflating a large bubble of glass, coating the interior surface with molten lead, and breaking the bubbles into fragments, which were trimmed to the desired shape and size.) (1)

3-D computer rendering of several linked projector components, with sequential images inserted.
It is believed that this artifact is a modular component of an ancient Roman “film” projector; 24 of these bronze "modules" comprised a rotating base, 80cm in diameter. As the device turns, light from a lamp is reflected through glass “animation” slides positioned in the “side slots,” casting a faint image on an adjacent wall or curtain.

ROMAN METALLURGY
Although metals and metal working had been known since the Bronze Age, the Romans pioneered the mass production of metal objects; arguably, this was their most important contribution to the field of metallurgy. Central Italy was not rich in metal ores, however, which necessitated excavating and shipping metals over vast trade networks to meet the Empire’s growing demands. (2)

“It is believed that metal procurement and manufacturing were controlled to some degree by the state during the Roman Empire,” writes Harold Kory Cooper, “with the army often being directly involved in the mining industry in areas new to Roman control. Apparently mines in Spain were run by leaseholders instead of large companies. By the time of Augustus (27 BC), there had been a change from larger companies to private individuals in the operation of mines.

“Though there were a number of state-controlled weapons and armor factories scattered throughout the Roman Empire,” adds Cooper, “armies became more self-reliant with regards to weapons and armor manufacture as they moved further away from large cities.” The archaeological record includes recycled military equipment, suggesting that the army was involved in metal reworking. (3)

Pliny the Elder, author of the encyclopedic Naturalis Historia, wrote in the first century AD about the reuse of scrap copper in Roman foundries. He noted that the metals were recast as armor, weapons or articles for personal use, such as bronze mirrors. (4)

The Romans employed a variety of metal casting techniques, most of which had already been in use for at least a few thousand years. An object such as the Roman projector “module” would have been created using a two-piece mold – which allowed for a more finished cast product – or with a cheaper type of mold made by covering an object in clay, and then cutting it open so the clay could be fired. The “lost wax” method, which required the use of beeswax, was generally reserved for more ornate, decorative items such as statues. (5)

The metal preference for small artifacts was bronze, an alloy consisting primarily of copper mixed with tin. Three objects, in particular, were produced by the Romans in large quantities and are found extensively in the archaeological record: garment fasteners or brooches known as fibulae; coins, made in the millions; and ingots, used for metal working and the production of tools and weapons. Small items such as buckles, handles, and ornaments (for horses, chariots, shields, belts, containers and furniture) are also plentiful.

Henry Jesionka, who reconstructed the Roman projection device, speculates that it could have been owned by a rich Roman collector in the provinces and may have played a ceremonial role in a temple dedicated to Sol, the sun god.  On the other hand, it may simply have been produced as a novelty item for amusement.

By the time of the start of the Roman Empire in 27 BC, Romans were voracious collectors. "Various concentrations of dealers emerged in Rome to capitalize on this collecting frenzy," writes Russell W. Berk, "with the most famous being the art dealers, booksellers, and antiques dealers of the Villa Publica. In addition to sculptures and paintings," writes Belk, Romans collected "Corinthian bronze statues and vessels, bronze tripod tables, silverware, ceramics, carpets, tapestries, embroideries, books, jewelry, gems and fine furniture. Those who could not afford to collect original art collected copies as well as coins, fossils, and natural curiosities, such as insects trapped in amber." (6)     


Notes:
 

1.   Whitehouse, David. Roman Glass in the Corning Museum of Glass, Volume 3. Hudson Hills Press: New York, 2003. p. 46.

2.     Wikipedia. “Roman Metallurgy." 2012. http://en.wikipedia.org/wiki/Roman_metallurgy

3.     Cooper, Harold Kory. “Analysis of Late Roman-Byzantine Copper Alloy Artifacts from Northern Jordan.” Master’s Thesis, University of Alaska Anchorage, 1997.

4.     The Trade Environment Database. “Roman Bronze Trade.” American University,1997.  http://www1.american.edu/ted/bronze.htm

5.    Cooper. op. cit.

6.   Berk, Russell W.  Collecting in a Consumer Society. Routledge: London and New York, 1995, p. 23